Prostatectomy for benign hypertrophy of the prostate is the major operation most commonly performed on male members of the Medicare Program. Prostatectomy lacks a firm base of scientific evidence regarding indications for use and outcomes. The objective is to show how non-experimental studies can produce useful information on the efficacy and effectiveness of prostatectomy and be used to provide the requisite information for designing a controlled clinical trial. Members of the research team have been engaged in evaluating the outcome of this operation in Maine using several strategies, including a literature review, cohort studies of mortality and complication rates using claims data, interview studies of patients for functional status assessment before and after surgery and interview studies of these patients' physicians to ascertain the reasons (clinical hypotheses) for undertaking the operation. The information from the patient interview studies will be further analyzed to develop indices of patient morbidity, symptoms, functional impairment and utilities and integrated, along with the results from the claims-based cohort study of mortality and complications into a decision analysis to evaluate the probabilities and utilities for the surgery and the natural history "arms" of the decision tree. The results of these various studies will be used to evaluate the need for a randomized clinical trial: which clinical hypotheses are urgently in need of experimental evaluation and what is the design of the experiment to test these hypotheses? The product of the grant will be a monograph which describes the various nonexperimental methodologies we have used, gives the principal results of these studies, and discusses the conclusions concerning the need for further study.